Nonwoven fabric

Abstract

It is an objective of the present invention to provide a nonwoven fabric prepared so as to be able to rapidly transfer a predefined liquid. The nonwoven fabric is formed by jetting a fluid, which consists mainly of gaseous matter, to a fiber web 100 supported from beneath by a predefined breathable support member, from an upper surface side in order to move fibers in the fiber web 100. A number of groove portions 1 and a number of convex portions 2 are formed on a jetted area of the nonwoven fabric in the direction in which the area is extended, and the fiber density of the groove portions 1 is less than the fiber density of the convex portions 2.

Description

[0001]This application is based on and claims the benefit of priority from Japanese Patent Application No. 2006-174505, filed on Jun. 23, 2006 and from Japanese Patent Application No. 2006-270106, filed on Sep. 29, 2006, the content of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to nonwoven fabrics.[0004]2. Related Art[0005]Nonwoven fabrics have been used in a wide variety of fields including sanitary materials such as diapers and sanitary napkins, cleaning products such as cleaning wipers and medical supplies such as masks. Nonwoven fabrics are used in various fields, as described above, and it is necessary for nonwoven fabrics to be produced so as to have characteristics and structures suitable for use in each product application.[0006]Nonwoven fabrics are formed, for example, by forming fiber layers (fiber webs) by using either a dry method or a wet method, and binding the fibers that are...

AI Technical Summary

Benefits of technology

[0011]In other words, manufacturing steps of the nonwoven fabrics or the method for manufacturing the nonwoven fabrics described in JP-A No. 3587831 are complicated because a number of fiber layers having different shapes are needed to form irregularities in fiber webs. Moreover, many heat sealed areas in the first and the second fiber layers must be sealed steadily, otherwise convex portions of the second fiber layer are not formed when the first and the second fiber layers fall away during heat contraction. This increases the density of the heat sealed areas, and the resultant film exhibits poor quick penetration characteristics of a predefined liquid, such as excretory substance, in that area. As a result, the predefined liquid is fed and collected into the concave portion and then transferred gradually inwards from the side surface of the concave portion. Furthermore, it is difficult for the predefined liquid to be rapidly transferred because the periphery of the concave portions is consolidated or formed into a film by heat embossing. For this reason, if a large quantity of the predefined liquid is being absorbed at a single moment, or if pressure is added to the nonwoven fabric, liquid may easily overflow from the concave portion. These are the subjects of the present invention.

[0033]Provided by the present invention is a nonwoven fabric in which a predefined liquid can be rapidly transferred and at least sparsity and density are adjusted.

Problems solved by technology

In other words, manufacturing steps of the nonwoven fabrics or the method for manufacturing the nonwoven fabrics described in JP-A No. 3587831 are complicated because a number of fiber layers having different shapes are needed to form irregularities in fiber webs.

This increases the density of the heat sealed areas, and the resultant film exhibits poor quick penetration characteristics of a predefined liquid, such as excretory substance, in that area.

Furthermore, it is difficult for the predefined liquid to be rapidly transferred because the periphery of the concave portions is consolidated or formed into a film by heat embossing.

For this reason, if a large quantity of the predefined liquid is being absorbed at a single moment, or if pressure is added to the nonwoven fabric, liquid may easily overflow from the concave portion.

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